From 1be7b55bb484a0f6611baafa3bb5969dd8ae0266 Mon Sep 17 00:00:00 2001
From: "Emilio G. Cota" <cota@braap.org>
Date: Wed, 14 Mar 2018 09:49:41 -0400
Subject: [PATCH] tcg: introduce **tcg_ctxs to keep track of all TCGContext's

Groundwork for supporting multiple TCG contexts.

Note that having n_tcg_ctxs is unnecessary. However, it is
convenient to have it, since it will simplify iterating over the
array: we'll have just a for loop instead of having to iterate
over a NULL-terminated array (which would require n+1 elems)
or having to check with ifdef's for usermode/softmmu.

Backports commit df2cce2968069526553d82331ce9817eaca6b03a from qemu
---
 include/uc_priv.h              | 11 ++++++++---
 qemu/accel/tcg/translate-all.c |  3 +--
 qemu/tcg/tcg.c                 |  6 +++++-
 qemu/tcg/tcg.h                 |  2 +-
 4 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/include/uc_priv.h b/include/uc_priv.h
index 069eb3ca..9dd79d4b 100644
--- a/include/uc_priv.h
+++ b/include/uc_priv.h
@@ -217,10 +217,15 @@ struct uc_struct {
     intptr_t qemu_host_page_mask;
 
     /* code generation context */
-    void *tcg_ctx;      // for "TCGContext tcg_ctx" in translate-all.c
-    void *tcg_init_ctx; // for "TCGContext init_tcg_contex" in translate-all.c
+    // translate-all.c
+    void *tcg_ctx;          // actually "TCGContext *tcg_ctx"
+    void *tcg_init_ctx;     // actually "TCGContext *init_tcg_contex"
     TBContext tb_ctx;
-    bool parallel_cpus; // for "bool parallel_cpus" in translate-all.c
+    bool parallel_cpus;
+
+    // tcg.c
+    void *tcg_ctxs;         // actually "TCGContext **tcg_ctxs"
+    unsigned int n_tcg_ctxs;
 
     /* memory.c */
     unsigned memory_region_transaction_depth;
diff --git a/qemu/accel/tcg/translate-all.c b/qemu/accel/tcg/translate-all.c
index b4b2f209..389bb6e0 100644
--- a/qemu/accel/tcg/translate-all.c
+++ b/qemu/accel/tcg/translate-all.c
@@ -169,7 +169,7 @@ static void cpu_gen_init(struct uc_struct *uc)
 {
     uc->tcg_init_ctx = g_malloc0(sizeof(TCGContext));;
 
-    tcg_context_init(uc->tcg_init_ctx);
+    tcg_context_init(uc, uc->tcg_init_ctx);
 }
 
 static void tb_clean_internal(struct uc_struct *uc, int i, void** lp)
@@ -880,7 +880,6 @@ void tcg_exec_init(struct uc_struct *uc, unsigned long tb_size)
     TCGContext *tcg_ctx;
 
     cpu_gen_init(uc);
-    uc->tcg_ctx = uc->tcg_init_ctx;
     tcg_ctx = uc->tcg_ctx;
     tcg_ctx->uc = uc;
     page_init(uc);
diff --git a/qemu/tcg/tcg.c b/qemu/tcg/tcg.c
index 58779c56..34f0faae 100644
--- a/qemu/tcg/tcg.c
+++ b/qemu/tcg/tcg.c
@@ -325,7 +325,7 @@ static const TCGHelperInfo all_helpers[] = {
 
 static void process_op_defs(TCGContext *s);
 
-void tcg_context_init(TCGContext *s)
+void tcg_context_init(struct uc_struct *uc, TCGContext *s)
 {
     int op, total_args, n, i;
     TCGOpDef *def;
@@ -387,6 +387,10 @@ void tcg_context_init(TCGContext *s)
     for (; i < ARRAY_SIZE(tcg_target_reg_alloc_order); ++i) {
         s->indirect_reg_alloc_order[i] = tcg_target_reg_alloc_order[i];
     }
+
+    uc->tcg_ctx = s;
+    uc->tcg_ctxs = &uc->tcg_ctx;
+    uc->n_tcg_ctxs = 1;
 }
 
 /*
diff --git a/qemu/tcg/tcg.h b/qemu/tcg/tcg.h
index 5dd61685..19c4f3ec 100644
--- a/qemu/tcg/tcg.h
+++ b/qemu/tcg/tcg.h
@@ -639,7 +639,7 @@ void *tcg_malloc_internal(TCGContext *s, int size);
 void tcg_pool_reset(TCGContext *s);
 TranslationBlock *tcg_tb_alloc(TCGContext *s);
 
-void tcg_context_init(TCGContext *s);
+void tcg_context_init(struct uc_struct *uc, TCGContext *s);
 void tcg_context_free(void *s);   // free memory allocated for @s
 void tcg_prologue_init(TCGContext *s);
 void tcg_func_start(TCGContext *s);